Spray dampener for lithographic offset presses



Feb. 27, 1951 H. E. MARsDl-:N

SPRAY DAMPENER FOR LITHOGRAPHIC OFFSET PRESSES 2 Sheets-Sheet 1 FiledFeb. 18, 1946 /laff e.. ov vv...

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2 SheetsTSheet 2 Il I UJJlLU H. E. MARSDEN SPRAY DAMPENER FORLITHOGRAPHIC OFFSET PRESSES Feb. 27, 1951 Filed Feb. 18, 1946 ZWx/evvof;Hof-ace E. Maz/salen 'f Aff/VJ.

Patented Feb. 27, 195531 UNITED STATES PATENT OFFICE SPRAY DAMPENER FORLITHOGBAPBIC OFFSET PRESSES Horace Edwin Marsden, London, EnglandApplication February 18, 1946, Serial No. 648,275 In Great BritainFebruary 26, 1945 (Cl. lOl-147) 3 Claims.

the printing surface and a solid carrier for the dampening liquid, inthe manner described'and claimed in parent British patent specificationNo. 574,595 of Aug. 25, 1946, and in the corresponding U. S. Patent No.2,448,226 of Aug. 31, 1948.

With that object in view the uuid pressure atomising nozzles adapted todirect sprays of finely atomised liquid in the form of a mist onto thesurface of the printing plate, are mounted in a consolidated structureupon a block shaped the entire width of the printing plate carried bythe cylinder Il.

The block lua is adapted to be suitably supported between the framemembers I of the press so that its external, preferably plain,longitudinal face, i. e. the face provided to carry'the adaptors 40a ofthe spray nozzles G lies parallel to the printing plate surface. Thesenozzles are member hereinafter referred to as manifold block in whichthe manifolds, i. e. the main passages supplying separately thedampening liquid, usually water under pressure, and the pressure fluid,usually consisting of compressed air, are integrally embodied togetherwith other necessary parts of the device as hereinafter more fullydescribed. p

Accordingly, the invention consists in having the manifolds for thesupply of the pressure gas and liquid under pressure respectively to thepassages feeding the spray nozzles, as well as the valves controllingsaid feed arranged to operate within the manifold block with which thespray nozzles proper are consolidated to form a substantially integralunit.

A practical form of construction of the invention is illustrated in theaccompanying drawings in which Fig. 1 represents a full cross-section ofthe consolidated dampening unit and Fig. 2 is a plan view thereof.

The main components of the spray unit as here illustrated as well as thecontrolling and actuating mechanism are substantially as described inthe parent U. S. and British patents referred to above. The atomisingdevice proper comprises as in the parent case, a series of c'ompressedspray nozzles G, each consisting of an outer or air diffusing collar 42and an inner or water nozzle 4I, with its flared terminal 41, theirrespective passages 46, 46a, converging to a common mixing chamber 41a.These nozzles are arranged to extend in a longitudinal plane so as toproject towards the printing plate surface carried by the cylinder i iwithout, however, contacting the latter.` By preference as shown, theyare mounted upon or substantially arranged within flanged adaptors 40a,which, in their turn, are mounted upon a block shaped member Illa hereinreferred to as the manifold block. This block may be cast, cut from thesolid or built up from suitable sections if desired to form a box-likestructure which is preferably rectangular in cross section as shown andof suillcient length to extend across preferably equally spaced and maybe arranged in a straight line asy shown in Fig. 2 or in a plurality ofrows banked one above the other.

As in the parent U. S. and British patents, the water and air feedpassages of these spray nozzles G are supplied from the main ducts ormanifolds 33 and 32 which in the present construction are embodied inthe manifold block Illa so as to extend longitudinally thereinsubstantially one above the other as shown or in any desired position.The ducts leading transversely from these manifolds to connect thelatter with the nozzle feeding passages, are governed by spring inuencedadjustable valves, i. e. valve 53 controlling the flow of compressed airfrom the manifold 32 to passages 45 and 46 via an air chamber 44 and aneedle valve 48 controlling the flow of water under pressure to theflaring terminal 41 of the water nozzle through a water chamber 40provided in the adaptor 40a. 'I'he stems of these valves 48 and 53 aretightly packed by glands which have their main body portions locatedwithin the manifold block Illa.

Again as in the parent U. S. and British patents, the spray from thenozzle G is enclosed in a spray guard S in the form of a box-likestructure interposed between the spray nozzles and the printing platecylinder Il s'o as to extend across the entire width of the latter butin the present arrangement shown, it is constructed to house the wholeatomising structure and part of the manifold block Illa to which it isdetachably secured in any desired manner. The bottom 1| is fitted with agutter |05 suitably connected to a ldrainpipe while the top of the guardis formed with an inset glass panel 12 through which the condition ofthe sprays can be readily inspected. Adjustable side shields 13 adaptedto close selected portions of the open side of the snrav guard S aresecured in place by set screws 14 which are screwed into the top frontedge of the guard analagous to the construction in the parent case.

The operating mechanism for each compound spray unit G comprises arocking lever 58 pivoted at 58a in a bracket 58h which is secured to therear face of the manifold block 10a as shown by screws or in any othersuitable manner. At its upper end each lever 58 carries a valveoperating lever proper 59 secured to the front face of which is a plate60 adapted to engage collars on the valve spindles 48 and 53 and toaetuate these valves when the lever 58 is rocked. The levers 58 arerocked simultaneously through a control shaft 82 extending parallel tothe manifolds 32 and 33 and carrying cams 8l secured to the shaft by setscrews set to engage adjustable cam followers 83 secured to the lowerextremities of the levers 58. This extremity of each lever is formed asan angle bracket into which a threaded spindle of the cam follower 63 isscrewed and the further end of the cam follower spindle carries aserrated wheel 84 which is engaged by a spring loaded plunger pin 65 sothat the cam follower spindle can readily be rotated to adjust the throwof the lever. The cam shaft 82 is rotated by a handle 88 and carries apointer 88 to indicate `the settingof the device on an indicator scale81, all of these parts of the operating and setting mechanism beingsubstantially as described in the parent U. S. and British patents. Thecam shaft 82 carrying the cams Bi is lournalled in swinging-bearingbrackets 15 which are pivotally mounted upon a transverse shaft 16a xedin and extending between side frames 10b. Working in conjunction withthe bearing brackets 85 is a throw-off cam 80 situated on the insideface of the frame Ib and adapted to rock on shaft 8| on which it is setthrough an extension piece 82 so as to be rocked from an on position incontact with a shoulder 15a on the swinging bracket to an olf positioncontrolled by a stop pin 84 secured to the frame I0b. This shaft 8| iscontrolled by a hand lever 83 and the bracket 15 is held in positionunder tension by springs 88. The operation and its control are againsubstantially as described in the parent U. S. and British patents. Adescription in greater detail does not therefore appear to be requiredsince it does not form any actual part of the main characteristicfeature of this invention.

It will be appreciated by those skilled in the art that by theconsolidation of the parts of the mechanism as herein described andillustrated, not only is a great deal of labour saved by the materialreduction of actual components and means for their assembly but moreespecially by the embodiment of the uid passages and manifolds within'the manifold block most of the packing means for rendering the devicewaterand air-tight hitherto necessary have been dispensed with, wherebythe manufacture is simplified and its precision is greatly enhanced.

I claim:

1. In a lithographie offset printing press having a printing cylinderand a printing plate carried thereby, a dampening device for sprayingatomized water directly ontov the printing plate carried by the printingcylinder, comprising in combination a block shaped member extendingacross the entire Width of said printing plate, a first manifoldembodied lengthwise within said block shaped member for supplying airunder pressure, a second manifold embodied lengthwise in this said blockshaped members parallel with said first manifold for the supply of waterunder pressure, a series of compound air and water spray jets fed fromsaid manifolds for spraying atomized water onto said printing plate, aseries of adapters for securingsaid compound spray jets integrally tosaid block shaped member, valves operating within said block shapedmember regulating the supply of air and water .from such manifoldstosaid spray jets and cam actuated means carried by said block shapedmember for mechanically controlling said valves for regulating thesupply of air and Water under pressure to said spray jets substantiallyas set forth.'

first manifold embodied lengthwise within said block shaped member forsupplying air under pressure, a second manifold embodied lengthwise insaid block shaped member parallel with said first manifold for thesupply of water under pressure, a series of compound air and water sprayjets fed from said manifolds for supplying atomized water to saidprinting plate, a series of adaptors for securing said compound sprayjets integrally to said block shaped member, valves operating withinsaid block shaped member regulating the supply of air and water fromsuch manifolds to the spray jets and cam actuated means carried by saidblock shaped member and operable for mechanically controllingpre-selectable valves for regulating the supply of air and water underpressure to a predetermined number of said spray jets for the dampeningof a preselected portion of the printing plate substantially as setforth.

3. In a lithographie offset printing press having a printing cylinderand a printing plate carried thereby, a dampening device for sprayingatomized water directly onto the printing plate carried by the printingcylinder, comprising in combination a block shaped member extendingacross the entire width of said printing plate, a first manifoldembodied lengthwise within said block shaped member for supplying airunder pressure, a secondmanifold embodied lengthwise in same said blockshaped member parallel with said first manifold for the supply of waterunder pressure, a series of compound air and water spray jets fed fromsaid manifolds for supplying atomized water to said printing plate,series of adaptors for securing said compound spray jets integrally tosaid block shaped member, valves operating Within said block shapedmember regulating the supply of air and water from such manifolds tosaid spray jets and cam actuated means comprising a series of rockinglevers carried by said block shaped member in engagement with thespindles of said regulating valves, a cam shaft carrying a correspondingseries of cams, cam followers on said rocking levers and adjusting meansassociated with said cam followers for throwing pre-selected ones ofsaid cam followers in and out of engagement with said cams according tothe area of opening in the spray guard adjusted for dampening of apre-selected portion of the printing. plate substantially as set forth.

HORACE EDWIN MARSDEN.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS

